Evaporative coolers are well known to the art. Such coolers rely upon the principle that hot, dry air forced through a medium that is saturated with water will release heat to evaporate some of that water, producing a stream of cooler, more humid air. Such coolers have existed for more than fifty years, and principally are used in desert and other semi-arid climates where the addition of humidity to the air is possible and desirable.
Typically, evaporative coolers are found in three basic forms. First are fixed cooling units that are typically mounted on the roof of a building to be cooled, with associated duct work associated with the cooler to vent cool, fresh air to the building. There also are window coolers that cool the area in which they are located. Finally, there are so-called portable units, which often are temporarily or permanently mounted in windows, to table-tops, or to other structures so that hot, dry air can be cooled directly in the rooms in which these coolers are operating.
Because these three types of coolers require that the cooling unit be mounted permanently or temporarily, they have not often been used to cool spaces that are not frequented by the operator, or spaces where cooling is desired only for short periods of time. For that reason, a cooler that is truly and conveniently portable, in that it can be moved readily from one location to another without the need for even temporary mounting, has been desired by the trade and by consumers.
The requirements for such a cooler are several. First, the cooler must be rugged to withstand frequent movement from room to room as it is moved during use. Second, the cooler must be capable of being used both indoors and outdoors, because certain environments in which it may be operated are exposed to the elements. Third, because the cooler will not be connected to a fixed water source, the cooler should be capable of being filled at remote sites, such as by a garden hose, and preferably refilled without the need for action by the operator. Finally, because the cooler will not be mounted in a window or other location that is out of the way of furniture, tool benches, or other similar provisions found in the spaces where the cooler will be used, it must not by its size and operation compromise the spaces in which it will operate, or inconvenience the operator of the cooler.